Q: Would a normal system (read: I'm not talking about Guix System or NixOS) allow you to install multiple branches/versions of the same software natively without introducing a lot of headaches?
A: No. This is literally unsupported.
Then, if using containers (or any other similar platform) allows one to breach that limitation, would it be fair to call containers (and their like) to be strictly limited/limiting in customization?